20+ Senior Software Engineer and Lead Interview Questions and Answers

Microservices are important for scalability, flexibility, and fault isolation. Real-time use cases include e-commerce, banking, and IoT.

• Microservices allow for independent development and deployment of small, focused services.

• They enable scalability by allowing each service to be scaled independently.

• Microservices provide flexibility to choose different technologies for different services.

• They facilitate fault isolation, as failures in one service do not affect others.

• Real-ti...read more

User authentication and authorization in MEAN stack is handled using Passport.js and JSON Web Tokens (JWT).

• Passport.js is used for authentication, providing various strategies like local, OAuth, etc.

• JWT is used for authorization, generating and validating tokens for authenticated users.

• User credentials are stored securely in the database, usually hashed and salted.

• Middleware functions are used to protect routes and verify JWT tokens.

• Access control can be implemented using rol...read more

Use dynamic programming to find the minimum steps to convert string a to b by deletion, insertion, or replacement.

• Create a 2D array to store the minimum steps required to convert substrings of a to substrings of b.

• Initialize the array with base cases for empty strings and iterate through the rest of the array to fill in the values based on previous calculations.

• The final value in the bottom right corner of the array will be the minimum steps required to convert the entire str...read more

Abstract is a class that cannot be instantiated, while abstract keyword is used to declare a method as abstract. Interface is a contract that defines methods that a class must implement.

• Abstract class cannot be instantiated, but can have concrete methods.

• Abstract keyword is used to declare a method as abstract, meaning it has no implementation.

• Interface is a contract that defines methods that a class must implement.

• A class can implement multiple interfaces, but can only exten...read more

Identify, isolate, analyze, and resolve production errors systematically.

• 1. Start by identifying the error message or symptom reported by users or monitoring tools.

• 2. Isolate the root cause by reviewing recent code changes, infrastructure updates, or third-party services.

• 3. Analyze logs, metrics, and system behavior to understand the context of the error.

• 4. Reproduce the error in a controlled environment if possible to test potential solutions.

• 5. Implement a fix or workaround...read more

WAP to find the three most occurred characters in the given string

• Create a hash table to store the frequency of each character

• Sort the hash table in descending order of frequency

• Return the top three characters with highest frequency

Aura is a component-based framework for building web apps in Salesforce, while LWC is a modern UI framework to develop web components.

• Aura is based on the Model-View-Controller (MVC) architecture, while LWC is based on the Web Components standard.

• Aura components have a larger bundle size compared to LWC components.

• LWC provides better performance and is easier to debug compared to Aura components.

• LWC supports modern JavaScript features like ES6+ and Shadow DOM, while Aura uses...read more

A full day hackathon focused on developing a Spring Boot REST API.

• Participants will work in teams to develop a REST API using Spring Boot.

• The hackathon will likely involve creating endpoints, handling requests and responses, and integrating with databases.

• Participants may also be asked to present their API and explain their design choices.

• The hackathon is a great opportunity to showcase technical skills and collaborate with other developers.

I have over 10 years of experience working on various projects in the software development field, including leading teams and implementing innovative solutions.

• Led a team of developers in the successful implementation of a new CRM system for a large e-commerce company

• Designed and developed a mobile application that increased user engagement by 30%

• Worked on a project to optimize database performance, resulting in a 50% decrease in query times

Polymorphism is the ability of a single function or method to operate on different data types.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example of compile-time polymorphism: function overloading in Java.

• Example of runtime polymorphism: method overriding in Java.

• Polymorphism helps in achieving flexibility and reusability ...read more

Yes, I can write Rest Api's

• I have experience in designing and developing Restful APIs using frameworks like Spring Boot, Django, and Flask

• I am proficient in HTTP methods, status codes, and authentication mechanisms

• I have worked with JSON and XML data formats

• I can write unit tests and integration tests for APIs

OOPs concepts are the fundamental principles of object-oriented programming.

• Encapsulation - binding data and functions together

• Inheritance - creating new classes from existing ones

• Polymorphism - ability of objects to take on multiple forms

• Abstraction - hiding implementation details from users

I have worked on various projects utilizing skills such as Java, Spring Boot, Angular, and AWS.

• Developed a web application using Java and Spring Boot for backend functionality

• Implemented front-end using Angular for user interface

• Utilized AWS services for cloud deployment and management

Batch processing is the execution of a series of jobs in a program without manual intervention.

• Batch processing involves processing large volumes of data at once

• Jobs are typically scheduled to run at specific times or intervals

• Commonly used in tasks like payroll processing, billing, and report generation

Interfaces in software engineering define a contract for classes to implement specific methods or properties.

• Interfaces in programming languages like Java, C#, and TypeScript allow for multiple inheritance by defining a set of methods that a class must implement.

• Interfaces provide a way to enforce a certain structure or behavior in classes that implement them.

• Interfaces are used to achieve loose coupling between classes, making code more maintainable and extensible.

• Example: I...read more

Python has a vast collection of libraries for various purposes including data manipulation, web development, machine learning, etc.

• NumPy for numerical computing

• Pandas for data manipulation

• Django for web development

• TensorFlow for machine learning

• Matplotlib for data visualization

Design a vending machine for dispensing snacks and drinks.

• Include a selection of snacks and drinks with corresponding prices

• Allow users to insert coins or bills to pay for items

• Dispense the selected item and return change if necessary

SOLID principles are a set of five design principles in object-oriented programming to make software more maintainable, flexible, and scalable.

• Single Responsibility Principle (SRP) - A class should have only one reason to change.

• Open/Closed Principle (OCP) - Software entities should be open for extension but closed for modification.

• Liskov Substitution Principle (LSP) - Objects of a superclass should be replaceable with objects of its subclasses without affecting the functiona...read more

Design a system to generate short URLs from long URLs

• Use a hashing algorithm to generate a unique short code for each long URL

• Store the mapping of short code to long URL in a database

• Redirect users from short URL to long URL when accessed

Node.js is a runtime environment that allows you to run JavaScript on the server side.

• Node.js is built on Chrome's V8 JavaScript engine.

• It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.

• Node.js is commonly used for building server-side applications, APIs, and real-time applications.

• It has a large ecosystem of open-source libraries and frameworks, such as Express.js and Socket.io.